ionic: fix double use of queue-lock

Deadlock seen in an instance where the hwstamp configuration
is changed while the driver is running:

[ 3988.736671]  schedule_preempt_disabled+0xe/0x10
[ 3988.736676]  __mutex_lock.isra.5+0x276/0x4e0
[ 3988.736683]  __mutex_lock_slowpath+0x13/0x20
[ 3988.736687]  ? __mutex_lock_slowpath+0x13/0x20
[ 3988.736692]  mutex_lock+0x2f/0x40
[ 3988.736711]  ionic_stop_queues_reconfig+0x16/0x40 [ionic]
[ 3988.736726]  ionic_reconfigure_queues+0x43e/0xc90 [ionic]
[ 3988.736738]  ionic_lif_config_hwstamp_rxq_all+0x85/0x90 [ionic]
[ 3988.736751]  ionic_lif_hwstamp_set_ts_config+0x29c/0x360 [ionic]
[ 3988.736763]  ionic_lif_hwstamp_set+0x76/0xf0 [ionic]
[ 3988.736776]  ionic_eth_ioctl+0x33/0x40 [ionic]
[ 3988.736781]  dev_ifsioc+0x12c/0x420
[ 3988.736785]  dev_ioctl+0x316/0x720

This can be demonstrated with "ptp4l -m -i <intf>"

To fix this, we pull the use of the queue_lock further up above the
callers of ionic_reconfigure_queues() and ionic_stop_queues_reconfig().

Fixes: 7ee99fc5ed2e ("ionic: pull hwstamp queue_lock up a level")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
index e91b487..3de1a03 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
@@ -582,7 +582,10 @@ static int ionic_set_ringparam(struct net_device *netdev,
 
        qparam.ntxq_descs = ring->tx_pending;
        qparam.nrxq_descs = ring->rx_pending;
+
+       mutex_lock(&lif->queue_lock);
        err = ionic_reconfigure_queues(lif, &qparam);
+       mutex_unlock(&lif->queue_lock);
        if (err)
                netdev_info(netdev, "Ring reconfiguration failed, changes canceled: %d\n", err);
 
@@ -679,7 +682,9 @@ static int ionic_set_channels(struct net_device *netdev,
                return 0;
        }
 
+       mutex_lock(&lif->queue_lock);
        err = ionic_reconfigure_queues(lif, &qparam);
+       mutex_unlock(&lif->queue_lock);
        if (err)
                netdev_info(netdev, "Queue reconfiguration failed, changes canceled: %d\n", err);
 

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index 23c9e19..381966e 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -1715,7 +1715,6 @@ static int ionic_set_mac_address(struct net_device *netdev, void *sa)
 static void ionic_stop_queues_reconfig(struct ionic_lif *lif)
 {
        /* Stop and clean the queues before reconfiguration */
-       mutex_lock(&lif->queue_lock);
        netif_device_detach(lif->netdev);
        ionic_stop_queues(lif);
        ionic_txrx_deinit(lif);
@@ -1734,8 +1733,7 @@ static int ionic_start_queues_reconfig(struct ionic_lif *lif)
         * DOWN and UP to try to reset and clear the issue.
         */
        err = ionic_txrx_init(lif);
-       mutex_unlock(&lif->queue_lock);
-       ionic_link_status_check_request(lif, CAN_SLEEP);
+       ionic_link_status_check_request(lif, CAN_NOT_SLEEP);
        netif_device_attach(lif->netdev);
 
        return err;
@@ -1765,9 +1763,13 @@ static int ionic_change_mtu(struct net_device *netdev, int new_mtu)
                return 0;
        }
 
+       mutex_lock(&lif->queue_lock);
        ionic_stop_queues_reconfig(lif);
        netdev->mtu = new_mtu;
-       return ionic_start_queues_reconfig(lif);
+       err = ionic_start_queues_reconfig(lif);
+       mutex_unlock(&lif->queue_lock);
+
+       return err;
 }
 
 static void ionic_tx_timeout_work(struct work_struct *ws)
@@ -1783,8 +1785,10 @@ static void ionic_tx_timeout_work(struct work_struct *ws)
        if (!netif_running(lif->netdev))
                return;
 
+       mutex_lock(&lif->queue_lock);
        ionic_stop_queues_reconfig(lif);
        ionic_start_queues_reconfig(lif);
+       mutex_unlock(&lif->queue_lock);
 }
 
 static void ionic_tx_timeout(struct net_device *netdev, unsigned int txqueue)